Two-Particle Interfacial Microrheology at Polymer−Polymer Interfaces

Abstract

We continue to develop two-particle interfacial microrheology and have applied the technique to study the interfacial viscoelastic properties of immiscible poly(dimethylsiloxane) (PDMS)-poly(ethylene glycol) (PEG) interfaces. The interfacial storage and loss moduli are measured over a wide frequency range: at low frequencies, the interfaces are dominated by viscous responses whereas elasticity dominates at high frequencies. The zero-shear interfacial viscosity, estimated following the Cox-Merz rule and Cross model, falls between the bulk viscosities of the two individual polymers. Surprisingly, the interfacial relaxation time, calculated from the crossover of the storage and loss moduli, is observed to be an order of magnitude larger than that of the PDMS bulk polymers. The effects of tracer particle surface chemistry and size have also been investigated and show minimum influences on two-particle interfacial microrheology.

Hard and soft colloids at fluid interfaces: Adsorption, interactions, assembly & rheology

“…by Shlomovitz et al [128], who choose to not immerse the probe particles inside the layer but close to it. Also two point interfacial microrheology has been applied in one study [129].…”

Non-Stick Length of Polymer–Polymer Interfaces under Small-Amplitude Oscillatory Shear Measurement

“…For air–liquid and liquid–liquid interfaces, several types of surface shear rheometries have been applied [ 10 , 11 ]. A microrheology technique has also been exploited for air–liquid and liquid–liquid interfaces [ 12 , 13 , 14 ]. Atomic force microscopy has been used to characterize the local rheological properties of the surface of polymeric materials [ 15 , 16 ].…”

Dynamic Shear Responses of Polymer-polymer Interfaces

“…An attempt to measure the dynamic modulus of polymer-polymer interfaces was reported. Song and Dai [20] applied a passive microrheology technique to an interface between polydimethylsiloxane and polyethylene glycol using Pickering emulsions at room temperature. In this technique, a tracer particle is confined to the interface region by physico-chemical absorption.…”